Butyrometer centrifuge



July 17 1951 G. w. RuDA 2,560,988

BUTYROMETER CENTRIFUGE Filed vec. 12, 194e 2 sheets-sneer 1 N Vf /V TOR GmsjzAr MLHELM Ram Filed Dec. 12, 1946 Gy'w. RuDA BuTYRoMETER CENTRIFUGE 2 Sheets-sheI 2 i FIG. I'

Patented July 1K7-, 1951 BUTYROMETER CENTRIFUGE Gustaf Wilhelm Ruda, Stockholm, Sweden, as-

signor to Aktiebolaget Separator, Stockholm, Sweden, a corporation of Sweden Application December 12, 1946, Serial No. 715,789 In Sweden March 1, 1945 4 Claims. l

This `invention relates to butyrometer centrifuges in which test tubes containing the butyrometer samples are held in the centrifugal bowl by means of a rack comprising superimposed plates defining radial pockets for the test tubes.

When using butyrometer centrifuges, water is -let into the centrifugal bowl in such a way as to flow radially outward from a central tube inthe -bowl to the outer wall of the bowl, and from there inward until the bowly isilled up to a certain level situated a little outside the inwardly directed lmouths in the necks of the test tubes. The water thus introduced into the bowl serves to control the" temperature of the contents of the test tubes. It .is important that water is not admitted into the mouths of the test .tubes before the centrifugation.

Therefore, the level to which the bowl is lled with Water should under no circumstances be allowed to lie inside the mouths before the centrifugation. To prevent this, the bowl is provided with an overflow discharge or water outlet at a suitable distance from the axis of rotation of the bowl. The water level, of course, tends to adjust itself at the same radius as this overflow discharge. However, with butyrometer centrifuges as constructed heretofore, it has been found in practice that the water level in the vicinity of the inlet to the bowl chamberfor receiving the test tubes will, under certain circumstances, be 1ocated too far inwardly and, in fact, inside the test tube mouths. This often causes water to flow into the mouths of some of the test tubes, causing -a liquid exchange between the content of the tubes and the water mass around them. Part of the milk fat in the test tube will then escape, with the result that the fat content in the tube, as measured after the centrifuging has been finished, will be less than what corresponds to the original fat content in the tube. The test will thus be erroneous.

The present invention, therefore, is directed to the provision of an improved butyrometer centrifuge which will overcome the above-mentioned difficulty. According to the invention, the bowl of the butyrometer centrifuge is provided with conveyors which insure complete conveying of the water from its inlet openings outwardly toward the outer portion of the bowl and then inwardly toward the overflow discharge. In this way, the conveyors act upon the water mass on its way through the bowl, to cause the water mass to rotate at the same angular speed as the bowl and thus prevent slipping, whereby the centrifugal force will affect all portions of the water mass in the same degree. Accordingly, the level of, the

, y2 water mass in the bowl will adjust itself substantially parallel to theaxis of rotation and will not reach the mouths of the test tubes by moving inside the radius of the overflow discharge.

The conveyors may conveniently be made in the. form of wings attached to the bowl top or `cover andl to the bottom of the bowl and extending, respectively, to the uppermost and lowermostplates of the holder rack. Alternatively, the vwings may be attached wholly or partly to the holder plates instead of the bowl walls.

For a better understanding of the invention, reference may be had to the accompanying drawing, in .which Fig. l is a vertical sectional view, partly in elevation, of one form of a centrifugal bowl arranged in accordance with the invention;

Figs. 2 is a vertical sectional view, taken on line 2-2 of Fig. 4, of part of the bowl illustrated in Fig. l, showing in detail the manner of arranging the conveyor wings above the uppermost holder plate;

Fig..3 is a view similar to Fig. 2 but taken on line 3 3 of Fig. 4, showing the manner of arranging the conveyor wings below the lowermost holder plate,v and the driving pinv within thatplate, and

Fig. 4 is a plan view of one of the intermediate plates shown in Fig. 1

Referring to the drawing, the numeral lfdesignates a centrifugal bowl adapted to be rotated about a central vertical axis, as by means of a driving spindle Il. Within the bowl is a rack comprising a plurality of superimposed plates l2, the lowermost of which has a driving connection from the bowl in the form of a hole I3a (Fig. 4) which receives a driving pin I3 seated in the bottom of the bowl. Each of the plates I2 has a peripheral driving and locating pin I4 engaged in a downwardly directed slot in the side wall of the next upper plate, whereby the nested plates are driven as a unit. Each pair of adjacent plates I2 defines a horizontal series of circumferentially spaced pockets I5 which are staggered with respect to the pockets in the next horizontal series. The pockets I5 are shaped to hold the test tubes I 6 in radial positions, with the necks and mouths of the respective tubes located near the axis of rotation.

Above the bowl I0 is a stationary water container I8 provided with a bottom valve I9 and a discharge pipe 20. The valve I9 is operable man ually to control the flow of water from the tank down through the pipe 20 and into the upper end v`of an inlet .tube or tubular shaft 2l in the bowl.

dially outward into the bowl chamber containingl the test tubes IB, the water filling the bowl chamber up to the level 23 defined by. the discharge holes 24a, in the plates. Thus, any additional water introduced through the inlet Zia, beyond that necessary to maintain thebowl chamber-- lled to the level 23, will discharge from thebowl chamber by way of these holes andbe conducted therethrough to an overflow discharge chamber 24 and leave the bowl through an outlet 25.

In order that the water jet from the inlet opening 2la shall continuel in theradial direction in relation to the bowl, aneiective conveying of the water is required along its whole passage. To provide-such a conveying, wings 21 are arranged radially between the uppermost plate l2 and the bowl top or cover 22, the conveying wings extending from the vicinity fthe tubular shaft 2l outwardly to the outer portionl ofthe bowl. As illustrated, each wing is divided along a plane 28 forming the inside of the bowl cover 22. The part of wing 21 locatedbelow the plane 28 is attached to the uppermost plate l2, while-the portion 29 above the planer 28 is attached to the bowl cover 22.

The outer part of the uppermost plate I2 has a number of holes 30 for admitting water into the space between the two uppermost plates. It will be understood that through corresponding holes 30a, in the plates below, the water passes on to the intermediate spaces between these plates. Each of the holder plates below the uppermost plate l2 is suitably ,provided with conveyor wings 21a.V

The lowermost lplate I2- rests directly on the bottom of the bowl. The tube pockets formed in the lower face of this plate serve as effective conveyors along the` major part of theV water path from the outer portion of the bowl to the overflow discharge 24. However, the region outside but adjacent to the overflow discharge is not covered by these pockets. Accordingly, in order to convey the water along this region as well, I provide a plurality of wings 32 which form radial extensions leading directly to the overflow discharge 24. As pointed out above, thewings 32 may be attached to the bottom of the bowl or they may be attached to the lowermost plate I2.

By arranging the wings 21 near the top of the bowl and the wings 32 near the botto'n of the bowl, and amxingV the wings 21d between the plate `I2, all in the mannerl described, I provide effective conveyors radiating from the regions of the water inlet and the water outlet, respectively, of '65 4the bowl, which act to cause the flowing water mass to rotate at lthe same angular velocity as the bowl. Asa result, the water level 23 in the bowl during the centrifuging is maintained in such a manner as to prevent the water from reaching the mouths of the test tubes and causing a liquid exchange with the contentsv ofthe tubes.

I claim: Y l

l. In combination with a centrifugal bowl, 'a

for receivingA test tubes,

tube holding rack in the bowl including a plurality of superimposed plates defining pockets for receiving test tubes, the plates having liquid flow passages extending through generally horizontal surfaces of the plates for serial ow of liquid through the pockets, the bowl having inlet and outlet openings for owing a liquid into the bowl, through the passages and pockets, and out of the bowl, and a plurality of radial conveying elements extending from the rack tothe upper wall of the bowl and from the rack to the lower wall of the bowl, said elements defining upper and lower channels communicating with said openings, respectively, and also with said passages, said conveying elements including wings secured to the uppermost plate of the rack and extending substantially radially with respect to the rotation axis of the bowl, said elements acting to bring about correspondence between the angular speed of the liquid flowing through the bowl and the. angular speed of .the bowl during thecentrifuging.

2. In combination with a centrifugal bowl, a tube holding rack in the bowl including aplural@ ity of superimposed plates.r defining pockets vfo: receivingvtest tubes, the plates havingQliquidflow passages extending throughr generally horizontal surfaces of the plates. for serial. flowV of liquid through the pockets, theabowl havingv inlet and outletopenings for flowing aliqu'id into thegbow-l. through the passages andv pockets, and out-fof the bowl, and a. plurality offradial conveying elegments extending from the rack vto the upper wall of the bowl and; from the rackto the lower wall of thev bowl, said elements ldefining upper and lower. channels communicatingwith said openf; ings, respectively, and4 also with said passages. the conveying elementsv -including a wing4 fixed to one of the end plates of: the rack, and an aligned wing fixed tothe adjacent-f horizontal wall of the bowl, said, elementsv acting to bring about correspondence between. the angularr speed of the liquid flowing through the bowl andthe angular speed'of thev bowl duringthe centrifuging. r

3. In combination' with ya centrifugal bowl, a tubeholding rack; in the fbowl includingV aplu,- rality ofk superimposed plates defining pockets for receiving testtubes, the plates having liquid ilow passages extending through generally horizontal surfacesf ofV the plates for serial, flow. of liquid through. the pockets, the bowl having inlet and outlet openings ,for how-ing a liquid into the bowl, through the passages and pockets, and out of the bowl, and: a pluralityof radial con;- veying elements extending lfrom therack to the upper wall ofthe bowl and froml the rack tothe lower wall of the bowl, said-elements defining upper and lower channels communicatingl with said openings, respectively, and also with. said passages, the upper wallof therbowl being in the form of a removable. cover, the conveying elet-- ments at the top of the bowl including a wing xed tothe uppermost plate:v ofl` the rack, and an aligned wing xed tothe cover, said eiementsacting to bring about correspondence between the angular speed off the liquid flowing through the bowl and the angular spf'aedl of the. bowl duringVV the centrifuging. 1

4. In combination 'vs'lith-` a centrifugal bowl,y a tube holding rack inthe bowl including 'a plurality of superimposed plates 'defining pockets the plates having. liquid flow passages extendingthrough4 generally hor-f- 'zontal Vsurfaces of'the"p1ates for serial Iflow 'et liquid through the pockets, the bowl having inlet and outlet openings for iowng a liquid into the bowl, through the passages and pockets, and out of the bowl, and a plurality of radial conveying elements extending from the rack to the upper wall of the bowl and from the rack to the lower wall of the bowl, said elements dening upper and lower channels communicating with said openings, respectively, and also with said pas sages, the conveying elements at the bottom of the bowl including relatively short wings fixed; to the lowermost plate of the rack, said elements acting to bring about correspondence between the angular speed of the liquid owing through 'the bowl and the angular speed 01 the bowl during 15 Number the centrifuging.

GUSTAF WILHELM RUDA.

6 REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 458,194 Sharples Aug. 25, 1891 506,838 Berg Oct. 17, 1893 559,055 Salenius Apr. 28, 1896 834,018 Nielson Oct. 23, 1906 1,212,168 Anker-Holth Jan. 16, 1917 1,321,288 Dalzell Nov. 11, 1919 FOREIGN PATENTS Country Date 20,859 Great Britain Dec. 28, 1889 349,710 Germany Mar. 6, 1922 

